diff --git a/Questions.txt b/Questions.txt
index d621552..6beb1af 100644
--- a/Questions.txt
+++ b/Questions.txt
@@ -90,7 +90,10 @@ Esto es una ecuación derivadas
 + Solve equation \frac{d^2 u}{dx^2}-x\frac{du}{dx}+u=0
 
 #08
-
+Preguntar si:
+(x, y) \ mapsto x ^ 2 + y ^ 2
+(x, y) \ mapsto x ^ 2-y ^ 2 + 2 x y ^ 2 + 1.
+Son correctos   
 
 #09